Disclosed herein is a method of producing an optically active thiophene-based compound using a simulated moving bed adsorption separation process, and more specifically, a method of continuously separating a racemic thiophene-based compound into its optically active thiophene-based compounds having high purity, through optical resolution using the simulated moving bed process. According to the method of the current invention, a racemic mixture of a thiophene-based compound can be continuously separated into its optically active thiophene-based compounds having high purity, which is an intermediate of optically active dorzolamide acting as a topical therapeutic agent for glaucoma, using a simulated moving bed adsorption separation technique, thereby increasing industrial usability.